Early during my kitchen gut/remodel, a plumber roughed in a drain for the dishwasher. It's 20" above the floor in the back of the dishwasher cabinet space (not proximate to the sink). It stubs out of the wall about three inches. As I attempted to install the dishwasher, I found that the drain is supposed to run out of the cabinet space no more than 4" or 6" above the floor (with a 20" high LOOP). This is according to the Kenmore installation instructions. Should the plumber redo this mistake at his expense or are my Kenmore drain setup constraints uncommon?